This invention relates to an internal combustion engine with spark ignition and at least one reciprocating piston, with an ignition device and at least one fuel delivery device per cylinder for direct fuel delivery essentially in the direction of the ignition device, and with at least one intake port generating a swirl movement in the combustion chamber bounded by a roof-shaped top face, the top surface of the piston being provided with an unsymmetrical, arched flow guiding rib assisting the swirl movement of the cylinder charge.